Method of controlling accumulation of sodium sulfate on the checker packing of a regenerator

Abstract

The instant invention provides a method of controlling the accumulation of sodium sulfate in the checker packing of a regenerator of a cross-fired regenerative-type glass melting furnace. Typically, glass batch materials are melted within the furnace by combustion of fuel. This combustion produces exhaust gas that is drawn through the regenerator and heats the checker packing. During the melting operation, sodium sulfate gas is formed by the melted glass and is carried with the exhaust gas through the regenerator. The sodium sulfate gas may condense on a portion of the checker packing. As the sodium sulfate condensate accumulates on the checker packing, it may restrict the flow of exhaust gas and/or combustion air through the regenerator. In the instant invention, a section of the regenerator which includes the portion of the checker packing with the condensed sodium sulfate is selectively heated to a temperature sufficient to melt the sodium sulfate, while any additional heating of remaining sections of the regenerator is minimized. In one embodiment of the invention, fuel is injected into a portion of the exhaust gas that passes through the section of the regenerator where the sodium sulfate condensate has accumulated. The fuel burns with the portion of the exhaust gas and heats the portion of the checker packing with the sodium sulfate build-up to melt the sodium sulfate.

We claim: 
     
       1. A method of controlling build-up of sodium sulfate in the checker structure of a regenerator of a cross-fired regenerative-type glass melting furnace, wherein glass batch materials are melted within said furnace by combustion of fuel which produces exhaust gas that is drawn through said regenerator and heats said checker packing, and wherein sodium sulfate gas from said melted glass is carried with said exhaust gas through said regenerator and said sodium sulfate gas condenses and accumulates within said regenerator on a portion of said checker packing, restricting gas flow through said portion of said checker packing, comprising; selectively heating a section within said regenerator which includes said portion of said checker packing to a temperature sufficient to melt said sodium sulfate, while   minimizing any additional heating of remaining sections within said regenerator.   
     
     
       2. The method as in claim 1 wherein a portion of said exhaust gas passes through said section of said regenerator and said heating step includes the step of injecting fuel into said portion of said exhaust gas, wherein said fuel burns with said portion of said exhaust gas and heats said portion of said checker packing as said portion of said exhaust gas passes through said section of said regenerator. 
     
     
       3. The method as in claim 2 wherein said temperature of said portion of said checker packing is increased during said heating step to at least about 1600° F. 
     
     
       4. The method as in claim 3 further providing a support structure for said checker packing and further including the step of controlling said heating of said section of said regenerator to prevent overheating of said support structure. 
     
     
       5. The method as in claim 4 wherein said controlling step includes the step of maintaining said support structure at a temperature of less than about 2000° F. 
     
     
       6. The method as in claim 3 wherein said injecting step includes the step of injecting about 2,000 to 15,000 SCFH of fuel. 
     
     
       7. The method as in claim 3 wherein said injecting step includes the step of injecting an amount of fuel sufficient to consume excess oxygen in said exhaust gas. 
     
     
       8. The method as in claim 3 wherein said exhaust gas is drawn downwardly through said regenerator and said injecting step includes the step of combining said fuel with said portion of said exhaust gas at an upper end of said regenerator above said portion of said checker packing. 
     
     
       9. The method as in claim 8 wherein said exhaust gas passes through a plenum positioned above said regenerator prior to being drawn downward through said regenerator and said combining step includes the step of combining said fuel with said portion of said exhaust gas within said plenum. 
     
     
       10. The method as in claim 3 further including the step of inserting a nozzle into said portion of said checker packing and said injecting step includes the step of injecting fuel directly into said portion of said checker packing while said portion of said exhaust gas passes through said section of said regenerator. 
     
     
       11. In a method of melting glass including the steps of feeding glass batch materials into a melting furnace, melting said batch materials within said furnace by combustion of fuel which produces exhaust gas, wherein said melting of said batch materials produces sodium sulfate gas which mixes with said exhaust gas, passing said exhaust gas from said furnace through a regenerator, transferring heat from said exhaust gas to packing within the regenerator, wherein said sulfate gas condenses and accumulates on selected sections of said packing within said regenerator which have a temperature of less than about 1600° F. restricting passage of gas through said regenerator, the improvement comprising: increasing said temperature of said selected sections of said regenerator to greater than about 1600° F. to melt said sodium sulfate which has condensed on said packing within said regenerator, while   minimizing any change in temperature within remaining sections of said regenerator.   
     
     
       12. The method as in claim 11 wherein portions of said exhaust gas pass through said selected sections of said regenerator and said increasing step includes the step of injecting fuel into said portions of said exhaust gas, wherein said fuel burns with said portions of said exhaust gas and increases said temperature of said selected sections of said regenerator as said portions of said exhaust gas pass through said selected sections of said regenerator. 
     
     
       13. The method as in claim 12 further providing a support structure for said packing and further including the step of controlling said temperature within said selected sections of said regenerator to prevent overheating of said support structure. 
     
     
       14. The method as in claim 13 wherein said controlling step includes the step of maintaining said support structure at a temperature of less than about 2000° F. 
     
     
       15. The method as in claim 12 wherein said injecting step includes the step of injecting about 2,000 to 15,000 SCFH of fuel. 
     
     
       16. The method as in claim 12 wherein said injecting step includes the step of injecting an amount of fuel sufficient to consume excess oxygen in said exhaust gas. 
     
     
       17. The method as in claim 12 wherein said exhaust gas is drawn downwardly through said regenerator and said injecting step includes the step of combining said fuel with said portions of said exhaust gas at an upper end of said regenerator above said selected sections of said regenerator. 
     
     
       18. The method as in claim 17 wherein said exhaust gas passes through a plenum positioned above said regenerator prior to being drawn downward through said regenerator and said combining step includes the step of combining said fuel with said portions of said exhaust gas within said plenum. 
     
     
       19. The method as in claim 12 further including the step of inserting nozzles into said selected sections of said regenerator and injecting fuel into said selected sections of said regenerator while said portions of said exhaust gas pass through said selected sections of said regenerator.